Currently, there are three known types of absorption refrigeration systems: The single-separation absorption system, the single absorption and recompression system, and the double-absorption system.
Of these three systems, the double-separation-effect absorption system is the one that permits obtaining the coefficient of frigorific performance (COP) which is defined as the ratio between the amount of heat absorbed at the cold source and the amount of calorific energy absorbed at the source of the highest motive heat.
This coefficient of frigorific performance, or COP, is thus representative of the output of the refrigeration system. Yet even with a double separation absorption refrigeration system the COP does not go beyond a value of 1 while in theory the COP should be able to reach a value of 1.3.